Yes Alpine Valley. The cops loved concerts up there. They would bust a couple hundred cars for open liquor on the way north, grab some dinner and a nap and then bust them for drunk driving on the way south.
The book focused more on the early influences, the California rock scene, who they were hanging with, that sort of stuff. I am always interested in how so many acts are intertwined. IIRC, Jackson Browne and Linda Ronstadt and the Eagles all hung out together. There was also some stuff on JD Sother (damn, forget the spelling) on how he was in and out of the group.
By-the-way, since there latest efforts have not sold very well, yet they have a following, are they an indie band now?